Network Topology and Elements of Network
The arrangement or connection patterns of computers or nodes or devices used in the network is known as network topology.The network topology describes how the computers and networking devices are linked with each other.
There are different types of network topology they are as follows:
1. Bus Topology
In this topology, all the computers are connected in a single cable.The common cable is known as network bus. The network interface card of each computer is connected to the network bus through a T-connector. The terminators are attached at both the end of the network bus.
- It is inexpensive and easy to install because all the computers in the network are attached to one single cable.
- The failure of one computer does not affect the performance of the rest of the networks
- Computers may be easily added or removed from the network.
- If a problem arises at any point of the cable, the entire network goes down.
- It tends to slow down under a heavy load.
- In this topology, troubleshooting could be difficult.
2. Star Topology
In this topology, all the computers are connected with switch/hub.It is the most popular topology used today. In star topology, twisted pair cable is used foe joining nodes and hub. Each nodes is connected individually in the network. When any nodes data or message, they reach to the destination node through the hub/switch.
- It is easy to add or remove computers from this topology.
- If one link fails in network, the other workstations are not affected.
- It is more reliable.
- In this topology, very high transmission rates is possible.
- It the central switch/hub fails, the whole network goes down.
- Long cable length is required, since each device is directly connected to the hub/switch.
- It may be costly to install since long length cable is required.
3. Ring topology
In this topology, all the computers or devices are connected to each other in a closed loop by single communication cable. Data transfer takes place in one direction from one node to another around the ring. It is also called loop network.
- Each computer does not have to depend on the central device as each computers controls transmission to and from itself.
- It has short cable connection which increases network reliability.
- It supports very high data transmission rate.
- It is difficult to change network structure.
- If a single computer fails, at least a portion of network wont work.
Elements of Network
- NIC (Network Interface Card) : It is a hardware device which contains electronic circuitry needed to ensure reliable communication between workstation and server.
- Hub: A hub is simply a multiport repeater and is the control component of the network transmission mode.
- Router: A router is a network connecting device. Although a router can transfer data between network that uses the same technology, it commonly transfers data between network using different technologies.
- Repeater: A repeater accepts weak signals, electrically regenerates them anhd then sends the message on their way.
- Bridge: A bridge is the connection of hardware and software that connects the network that uses similar communication system.
- Bandwidth: It is the amount of data that can be transmitted through communication channel in a fixed time period. It is expressed in Hertz.
- Server: Server is the main computer that provides services, data and other resources to other computers.
- Workstation: It is the place where the client works. It requests services, data and other resources to other computers.
- Modem (Modulator Demodulator) : It is a device which converts analog data to digital and vice -versa.
- Gateway: A gateway is a network connecting device that interconnects two networks using different technologies.
A protocol is a set of rule for communicating across the internet.
List of protocol
- HTTP (Hypertext Transfer Protocol)
- FTP (File Transfer Protocol)
- SMTP (Simple Mail Transfer Protocol)
Things to remember
- The arrangement or connection patterns of computers or nodes or devices used in the network is known as network topology
- In this topology, all the computers are connected in a single cable.
- In star topology, all the computers are connected with switch/hub.
- In ring topology, all the computers or devices are connected to each other in a closed loop by single communication cable.
- It includes every relationship which established among the people.
- There can be more than one community in a society. Community smaller than society.
- It is a network of social relationships which cannot see or touched.
- common interests and common objectives are not necessary for society.
Videos for Network Topology and Elements of Network
What is a Computer Network?
Computer Networking Tutorial - 13 - Ring Topology
Computer Networking Tutorial - 14 - Star Topology
Computer Networking Tutorial - 15 - Mesh Topology
Questions and Answers
The network topology is the cabling pattern of interconnection of computers on the network. It can be defined as the physical layout of cabling for connecting computers and other network devices on the network which describe how the computers and networking devices are linked with each other and how they communicate.
The three topologies are as follows:
- Bus topology
- Ring topology
- Star topology
The topology in which nodes are connected in a daisy chain by a linear sequence of buses which is formed by joining many segments of coaxial cables with BNC jacks and T-connectors is known as bus topology.
The disadvantages of bus topology are as follows:
- The entire network does not work if there is problem in any segment of the network bus.
- It is difficult to find fault.
- It provides limited flexibility for change.
The star topology is the most popular network topology used to connect computers and other network devices in which nodes are connected to a centrally-located device called hub in the form of star.
The advantages of star topology are as follows:
- If any node fails, it does not affect the remaining portion of the network.
- It can be extended easily to any size.
- There is less chance of failure of nodes due to cables, connectors, and other networking devices.
Protocols are set of rules or language that the computer uses on the network to communicate and exchange data with each other. The network protocol manages and controls how communication between computers on the network takes place.
The common protocols are:
1) ARP (Address Resolution Protocol)
2) POP (Post Office Protocol)
3) FTP (File Transfer Protocol)
4) NetBEUI (NetBIOS Extended User Interface)
5) IPX/SPX (Internet Packet Exchange/ Sequential Packet Exchange)
6) SMTP (Simple Mail Transfer protocol)
7)HTTP (Hyper Text Transfer Protocol)
8) TCP/IP (Transmission Control Protocol/ Internet Protocol)
The bandwidth defines the amount of data transmitted per second through the communication channel or the data handling capacity of a communication system.
A client is a network computer that utilizes the resources of other network computers, including other clients. The client computer has its own processor, memory and storage and can maintain some of its resources and perform its own tasks and processing. A server is a computer on the network which controls and manages other computers on the network. It is provides facilities of the sharing of data, software and hardware resources to other computers. The server computer must be powerful computer having higher processing and storage capacity.
A hub is a network devices having multiple connecting ports or pints. It is used to connect computers or other network devices through its ports. It acts as a central point for different computers and other devices. Hub is mostly used in the connected nodes.
A switch is a networking device that has multiple connecting ports like hub. It is used to connect computers, network devices and network segments. A switch can determine source and destination of the data packets. It does not transmit the data packets to all nodes connected on the network like a hub does. It reduces network traffic and improves the network filtering and performance better.
A bridge is a network device that connects the different network segments or different network having same protocol. Multiple bridges can be used to form a large network by connecting several small networks. It also filters the data or cheeks incoming signals and decides whether to forward the signals or reject them.
A router is a network device that amplifies the incoming signals, creates a new copy of it and transmits the signals on the network. As the cabling distance the electric signals become weak on the network, in such a case a repeater is used to amplify the weak signals.
A repeater is a network device that amplifies the incoming signals, creates a new copy of it and transmits the signals on the network. As the cabling distance the electric signals become weak on the network, in such a case a repeater is used to amplify the weak signals.
Gateway is a dedicated server that connects two networks having dissimilar communication protocols. The gateway computer accepts the data packets from a network and forward to destination network.
Modem stand for Modulator Demodulator. It is a network device that transfers data from one computer to another trough telephone line. A modem can convert digital signals into analog signals and vice versa. The conversion of digital signal into analog is modulation and an analog signal into digital is demodulation.
A network interface card (NIC) is the adapter through which a computer is connected to a network. It should be installed in one of the empty expansion slots of a motherboard but is built-in in the present motherboard. Each NIC is assigned a unique MAC (Media Access Control) address by the manufacturer through which data is sent to the destination. It controls the flow of data in the computer network.
In ring topology, all computers and other devices are connected in the shape of a circle without any end point. Computers are connected together in a closed loop or a ring and signals are transmitted in one direction.
1) It is easy to setup and reconfigure.
2) High speed of data transmission.
1) It is difficult to add or remove any node from the network.
2) Failure of any cable or computer may affect the whole network.